Copyright Authorization
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by any one of the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
1. Field of Invention
The field of the present invention relates in general to the field of wireless broadcast of information using one or more multiple access protocols and in particular to methods and apparatus for implementing spatial multiplexing in conjunction with the one or more multiple access protocols during the broadcast of information.
2. Description of the Related Art
In wireless broadcast systems, information generated by a source is transmitted by wireless means to a plurality of receivers within a particular service area. The transmission of such information requires a finite amount of bandwidth, and in current state of the art transmission of information from different sources, must occur in different channels.
Since there are quite a few services (e.g. television, FM radio, private and public mobile communications, etc.) competing for a finite amount of available spectrum, the amount of spectrum which can be allocated to each channel is severely limited. Innovative means for using the available spectrum more efficiently are of great value. In current state of the art systems, such as cellular telephone or broadcast television, a suitably modulated signal is transmitted from a single base station centrally located in the service area or cell and propagated to receiving stations in the service area surrounding the transmitter. The information transmission rate achievable by such broadcast transmission is constrained by the allocated bandwidth. Due to attenuations suffered by signals in wireless propagation, the same frequency channel can be re-used in a different geographical service area or cell. Allowable interference levels determine the minimum separation between base stations using the same channels. What is needed is a way to improve data transfer speed in the multiple access environments currently utilized for wireless communications within the constraints of available bandwidth.